Help with resetting island

Hey all,

I recently just got my nintendo switch lite second hand from eBay and got anima crossing.

Even though I deleted the old owners account and bought animal crossing on my own account, it keeps trying to put me on their island. It lets me make my own person, but i cannot travel to anywhere but their island.

It doesn’t let me move island in the settings because i apparently need a house on this persons island to be able to move.

I tried getting rid of all the data and starting over, but it still makes me go back to their island.

I want to have my own island, not play on someone else’s. Can someone help me?